JPWO2010107055A1 - Radio base station apparatus, radio communication system, radio communication method, and program - Google Patents

Abstract

Interference between the macro radio base station apparatus and the home radio base station apparatus is avoided, and a decrease in frequency carriers that can be used in the macro radio base station apparatus is suppressed. The radio communication system covers a first radio base station apparatus that covers the first cell and a second cell that is wider than the first cell and overlaps the first cell at least in part. A second radio base station apparatus, and the first radio base station apparatus refers to the communication quality of the second cell when communicating with a mobile station terminal included in the first cell. When it is determined that the radio resource reservation of the radio base station apparatus is necessary, a radio resource allocation request including the necessary resource amount is transmitted to the second radio base station apparatus, and the second radio base station apparatus When a radio resource allocation request is received from one radio base station apparatus, radio resources corresponding to the necessary resource amount are allocated to the first radio base station apparatus.

Description

[Description of related applications]
The present invention is based on the priority claim of Japanese Patent Application: Japanese Patent Application No. 2009-064792 (filed on Mar. 17, 2009), the entire contents of which are incorporated herein by reference. Shall.
The present invention relates to a radio base station apparatus, a radio communication system, a radio communication method, and a program, and in particular, a small radio base station apparatus, a macro radio base station apparatus, a radio communication system including these, a radio communication method of these, and Regarding the program.

  A home radio base station apparatus (Home eNode B, HeNB) is a radio base station apparatus that can be used only by a limited user such as a home or a small office (SOHO, cafe, etc.). The home wireless base station device deploys a wireless base station device of an LTE (Long Term Evolution) system in the home based on the LTE scheme. Only a limited number of users can occupy a small number of radio resources by using the home radio base station apparatus. Therefore, according to the home wireless base station apparatus, the user can experience high-speed data communication as compared with portable wireless communication in a conventional general network.

  The home wireless base station device is also installed in each home in the area already covered by the macro wireless base station device covering a wide area. Therefore, the area covered by the macro radio base station apparatus and the area covered by the home radio base station apparatus may overlap.

  When installing a home wireless base station device, avoid interference between a macro wireless base station device covering an area with a radius of several hundred meters to several tens of kilometers and a home wireless base station device, and It is necessary to avoid interference between radio base station apparatuses. In fact, the following interference can occur:

  First, a downlink channel transmitted by a macro radio base station apparatus (or an adjacent home radio base station apparatus) becomes interference for a mobile station terminal connected to the home radio base station apparatus. Secondly, the downlink channel transmitted by the home radio base station apparatus becomes interference for the mobile station terminal connected to the macro radio base station apparatus (or the adjacent home radio base station apparatus). Third, the uplink channel transmitted by the mobile station terminal connected to the home radio base station apparatus becomes interference for the macro radio base station apparatus (or the adjacent home radio base station apparatus). Fourth, an uplink channel transmitted by a mobile station terminal connected to a macro radio base station apparatus (or an adjacent home radio base station apparatus) becomes interference for the home radio base station apparatus.

  In order to deal with this problem, in the home wireless base station apparatus of WCDMA (Wideband Code Division Multiple Access) method, it is considered to avoid the problem by using the following method.

  The first method uses a frequency used by the home radio base station apparatus, a frequency different from the frequency used by the macro radio base station apparatus, or selects a frequency having a low interference level as much as possible. It is. A frequency with a low interference level refers to a frequency with low radio field intensity when a downlink channel is monitored by a home radio base station apparatus. This method is realized by monitoring a neighboring cell by a home radio base station apparatus and selecting an appropriate frequency.

  The second method is a method of selecting a scrambling code different from the scrambling code used by the macro radio base station apparatus as the scrambling code used by the home radio base station apparatus. This method is also realized by monitoring neighboring cells by the home wireless base station apparatus and selecting an appropriate scrambling code.

  Patent Document 1 describes a mobile communication system that easily realizes high communication quality and securing the number of user connections.

JP 2003-250178 A

The entire disclosure of Patent Document 1 is incorporated herein by reference.
The following analysis was made by the present inventors.

  The WCDMA system is a system in which a frequency is divided into fixed frequency bands (5 MHz) and used as separate frequency bands such as frequency # 1 and frequency # 2. On the other hand, the LTE system is a system that realizes a maximum data rate (over 100 Mbps) by bundling and using all available frequency bands (up to 20 MHz). Therefore, in the LTE system, the frequency band used by the macro radio base station apparatus and the home radio base station apparatus cannot be easily divided as in the WCMDA system.

  In addition, since WCDMA uses a Code Division Multiple Access (CDMA) system, even when the same frequency band is used, the scrambling code (Scramble Code) can be divided to increase the tolerance to interference. it can. On the other hand, since the LTE scheme employs an Orthogonal Division Multiple Access (OFDMA) scheme, there is no interference resistance improvement measure that divides the scrambling code as in WCDMA.

  Therefore, according to the LTE scheme, when the frequency bands used between the macro radio base station apparatus and the home radio base station apparatus overlap, the downlink radio wave of each apparatus and the mobile station connected to each apparatus There is a risk that uplink radio waves from the terminals interfere with each other and degrade the communication quality.

  In order to solve such a problem, as described above, it is conceivable that the frequency band used by the macro radio base station apparatus and the home radio base station apparatus is allocated in a fixed manner.

  However, for example, when a limited frequency band assigned to each operator is fixedly assigned to a home radio base station device such as 5 MHz and a macro radio base station device such as 15 MHz, the macro radio base station device The maximum data rate (over 100 Mbps) using 20 MHz cannot be provided. This is an unacceptable constraint for operators who expect data rates of over 100 Mbps. Further, according to the method of simply dividing the frequency band, it is difficult to cope with a case where several tens to several hundreds of home wireless base station devices exist under one macro wireless base station device.

  Therefore, a first radio base station apparatus (for example, a home radio base station apparatus) that covers the first cell and a cell that is wider than the first cell and at least partially overlaps the first cell While avoiding interference with a second radio base station apparatus (for example, a macro radio base station apparatus) that covers the second cell, a decrease in frequency carriers that can be used in the second radio base station apparatus is suppressed. Is a problem. An object of the present invention is to provide a radio base station apparatus, a radio communication system, a radio communication method, and a program that solve such problems.

A wireless communication system according to a first aspect of the present invention is:
A first radio base station apparatus covering a first cell;
A second radio base station apparatus that covers a second cell that is wider than the first cell and at least partially overlaps the first cell;
When the first radio base station apparatus communicates with the mobile station terminal included in the first cell, the radio resource of the second radio base station apparatus is reserved by referring to the communication quality of the second cell. When determining whether or not to reserve a radio resource and transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus,
When the second radio base station apparatus receives a radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus allocates radio resources according to the required resource amount to the first radio base station apparatus.

The radio base station apparatus according to the second aspect of the present invention is:
A radio base station apparatus covering a first cell,
When communicating with a mobile station terminal included in the first cell, refer to the communication quality of the second cell that is wider than the first cell and at least partially overlaps the first cell. Determining whether or not to reserve the radio resource of the second radio base station apparatus covering the second cell and determining that the radio resource reservation is necessary, it is necessary for the second radio base station apparatus. A radio resource allocation request including the resource amount is transmitted.

The radio base station apparatus according to the third aspect of the present invention is:
A second radio base station apparatus that covers a second cell that is wider than the first cell covered by the first radio base station apparatus and at least partially overlaps the first cell. ,
When a radio resource allocation request including a necessary resource amount is received from the first radio base station device in the first radio base station device, the radio resource corresponding to the necessary resource amount to the first radio base station device Assign.

A wireless communication method according to a fourth aspect of the present invention is:
When the first radio base station apparatus that covers the first cell communicates with the mobile station terminal included in the first cell, the first radio base station apparatus is a cell wider than the first cell and at least partially in the first cell. Determining whether or not to reserve radio resources of a second radio base station apparatus covering the second cell with reference to the communication quality of the second cell overlapping with the first cell;
When the first radio base station apparatus determines that a radio resource reservation is necessary, a step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus;
When the second radio base station apparatus receives a radio resource allocation request from the first radio base station apparatus, allocating radio resources according to the required resource amount to the first radio base station apparatus; including.

A wireless communication method according to a fifth aspect of the present invention is:
When the first radio base station apparatus that covers the first cell communicates with the mobile station terminal included in the first cell, the first radio base station apparatus is a cell wider than the first cell and at least partially in the first cell. Determining whether or not to reserve radio resources of a second radio base station apparatus covering the second cell with reference to the communication quality of the second cell overlapping with the first cell;
And a step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus when the first radio base station apparatus determines that the radio resource reservation is necessary. .

A wireless communication method according to a sixth aspect of the present invention is:
A second radio base station apparatus that covers a second cell that is wider than the first cell covered by the first radio base station apparatus and at least partially overlaps the first cell, Receiving, from the first radio base station apparatus, a radio resource allocation request including a resource amount required in one radio base station apparatus;
A second radio base station apparatus allocating radio resources according to a necessary resource amount to the first radio base station apparatus.

The program according to the seventh aspect of the present invention is:
When communicating with a mobile station terminal included in the first cell covered by the first radio base station apparatus, the cell is wider than the first cell and at least partially overlaps the first cell. Determining whether or not to reserve radio resources of the second radio base station apparatus that covers the second cell with reference to the communication quality of the second cell;
When it is determined that a radio resource reservation is necessary, a process of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus is sent to the CPU of the first radio base station apparatus. Let it run.

The program according to the eighth aspect of the present invention is:
Processing for receiving from the first radio base station apparatus a radio resource allocation request including a resource amount required in the first radio base station apparatus covering the first cell;
A process of allocating radio resources according to a required resource amount to the first radio base station apparatus, and a second cell that is wider than the first cell and overlaps the first cell at least in part The CPU of the second radio base station apparatus to be covered is executed.

  According to a radio base station apparatus, a radio communication system, a radio communication method, and a program according to the present invention, a first radio base station apparatus (for example, a home radio base station apparatus) that covers a first cell, and a first Interference with a second radio base station apparatus (for example, a macro radio base station apparatus) that covers a second cell that is wider than at least a portion of the cell and overlaps the first cell at least in part In addition, it is possible to suppress a decrease in frequency carriers that can be used in the second radio base station apparatus.

It is a figure which shows the structure of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the macro radio base station apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the other structure of the home radio base station apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows roughly the radio | wireless band used by the macro radio base station apparatus and home radio base station apparatus which concern on the 2nd Embodiment of this invention. It is a figure which shows the unit of the radio | wireless resource managed by the black radio base station apparatus and home radio base station apparatus which concern on the 2nd Embodiment of this invention. It is a figure which shows the radio channel used in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the home radio base station apparatus which concerns on the 2nd Embodiment of this invention. 7 shows a sequence chart of resource allocation and resource release between a home radio base station apparatus and a macro radio base station apparatus according to a second embodiment of the present invention. It is a figure which shows the structure of the resource allocation request | requirement in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the macro radio base station apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the resource allocation process by the macro radio base station apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the resource allocation process by the macro radio base station apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the resource allocation response in the 2nd Embodiment of this invention. It is a figure for demonstrating the resource allocation method in the 2nd Embodiment of this invention. It is a figure for demonstrating the resource allocation unit in the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the home radio base station apparatus which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating the resource allocation method in the 4th Embodiment of this invention. It is a figure for demonstrating the resource allocation unit in the 5th Embodiment of this invention.

  The radio communication system according to the first development form is preferably the radio communication system according to the first aspect.

  In the radio communication system according to the second deployment mode, it is preferable that the communication quality is the radio wave intensity and the propagation loss in the downlink reference channel of the second cell.

  The radio communication system according to the third deployment mode reserves downlink radio resources of the second radio base station apparatus when the first radio base station apparatus has a radio field intensity equal to or higher than a predetermined threshold. Is preferred.

  In the radio communication system according to the fourth embodiment, the first radio base station apparatus reserves uplink radio resources of the second radio base station apparatus when the propagation loss is equal to or greater than a predetermined threshold. Is preferred.

  In the radio communication system according to the fifth deployment mode, the necessary resource amount may be a resource amount that satisfies the maximum data rates in the uplink and downlink directions supported by the first radio base station device.

  In the radio communication system according to the sixth deployment mode, the necessary resource amount may be a resource amount according to a service type requested from the mobile station terminal.

  In a radio communication system according to a seventh development mode, the necessary resource amount is a resource amount according to a service type requested from a higher-level control device of the first radio mobile station device and the second radio mobile station device. There may be.

  In the radio communication system according to the eighth deployment mode, when the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the above-mentioned necessity is given to the first radio base station apparatus. It is preferable to allocate the maximum radio resource that can be allocated and is less than a certain amount of resources.

  In the wireless communication system according to the ninth development form, when the second wireless base station device receives a wireless resource assignment request from the first wireless base station device, the third wireless device that has already assigned wireless resources. When the third cell and the first cell covered by the base station do not overlap with each other, the radio resource that overlaps at least partially with the radio resource allocated to the third radio base station is assigned to the first radio. Preferably, it is assigned to a base station.

  The radio communication system according to the tenth embodiment is configured so that each time the second radio base station apparatus receives a radio resource allocation request from the first radio base station apparatus, radio resources of a predetermined resource amount are sequentially allocated. May be.

  In the radio communication system according to the eleventh embodiment, the second radio base station apparatus may allocate radio resources in units of resource blocks.

  In the radio communication system according to the twelfth embodiment, the second radio base station apparatus may allocate radio resources in units of subframes.

  In the radio communication system according to the thirteenth development mode, the first radio base station device and the third radio base station device may be home radio base station devices.

  In the radio communication system according to the fourteenth development mode, the second radio base station apparatus may be a macro radio base station apparatus.

  The 15th deployment radio base station apparatus is preferably the radio base station apparatus according to the second aspect.

  The radio base station apparatus according to the sixteenth development form is preferably the radio base station apparatus according to the third aspect described above.

  The wireless communication method according to the seventeenth development form is preferably the wireless communication method according to the fourth aspect.

  The radio communication method according to the eighteenth embodiment is preferably the radio communication method according to the fifth aspect.

  The wireless communication method according to the nineteenth embodiment is preferably the wireless communication method according to the sixth aspect.

  The program according to the twentieth development form is preferably a program according to the seventh aspect.

  The program in the twenty-first development form is preferably a program according to the eighth viewpoint. In addition, according to this invention, the computer-readable recording medium which recorded the said program is provided.

(Embodiment 1)
A wireless communication system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a wireless communication system according to the present embodiment. Referring to FIG. 1, the radio communication system 10 includes a first radio base station apparatus 11 and a second radio base station apparatus 12.

  The first radio base station apparatus 11 covers the first cell 21. On the other hand, the second radio base station apparatus 12 covers a second cell 22 that is wider than the first cell 21 and overlaps the first cell 21 at least partially.

  When the first radio base station apparatus 11 communicates with a mobile station terminal included in the first cell 21, the first radio base station apparatus 11 refers to the communication quality of the second cell 22 and the second radio base station apparatus 12 It is determined whether or not radio resources should be reserved. The first radio base station apparatus 11 transmits a radio resource allocation request including a necessary resource amount to the second radio base station apparatus 12 when it is determined that a radio resource reservation is necessary.

  When the second radio base station apparatus 12 receives a radio resource allocation request from the first radio base station apparatus 11, the second radio base station apparatus 12 allocates radio resources according to the required resource amount to the first radio base station apparatus 11. .

(Embodiment 2)
A wireless communication system according to a second embodiment of the present invention will be described with reference to the drawings.

(Constitution)
FIG. 2 is a diagram illustrating the configuration of the wireless communication system according to the present embodiment. Referring to FIG. 2, the radio communication system includes a macro radio base station apparatus (eNB) 200, home radio base station apparatuses (HeNB) 300 to 302, and a gateway / handover control apparatus (SGW / MME) 100. .

  The macro radio base station apparatus (eNB) 200 covers a relatively wide area of several hundred meters to several kilometers. The home wireless base station apparatuses (HeNBs) 300 to 302 cover a narrow area such as a home of several meters to several tens of meters. The SGW / MME 100 is a host device of the eNB 200 and the HeNBs 300 to 302, and performs data transfer within the LTE system and to other communication systems.

  The eNB 200 has a cover area 210. The HeNBs 300 to 302 have respective cover areas 310 to 312. Cover areas 210 and 310 to 312 include several to several hundred mobile station terminals 400 to 405, respectively.

  FIG. 3 is a block diagram illustrating a configuration of the eNB 200 according to the present embodiment. The eNB 200 includes a transport transmission / reception unit 220, a control unit 221, a resource scheduling unit 222, and a radio signal transmission / reception unit 223.

  eNB200 communicates with SGW / MME100 which is a high-order apparatus via a wire. The transport transmission / reception unit 220 controls transmission / reception of data on a wire.

  The eNB 200 communicates with the mobile station terminal 400 via radio. The wireless signal transmission / reception unit 223 performs wireless data transmission / reception control.

  The resource scheduling unit 222 performs scheduling (resource scheduling) so that radio resources used when transmitting and receiving radio signals with the mobile station terminal 400 do not overlap between the mobile station terminals.

  The control unit 221 manages each of these functional blocks.

  FIG. 4 is a block diagram illustrating a configuration of the HeNB 200 according to the present embodiment. The configurations of the HeNBs 301 and 302 are the same as the configuration of the HeNB 300.

  FIG. 4 shows a configuration of the HeNB 300 when exchanging messages with the eNB 200 via radio. In this case, the HeNB 300 includes a transport transmission / reception unit 320, a control unit 321, a mobile station terminal communication unit 322, an eNB communication unit 323, and a downlink channel reception analysis unit 324.

  The transport transmitter / receiver 320 transmits / receives data on a wire. The mobile station terminal communication unit 322 transmits and receives signals to and from the mobile station terminal 403. The eNB communication unit 323 transmits and receives radio signals to and from the eNB 200. The downlink channel reception analysis unit 324 receives and analyzes a downlink channel transmitted by an adjacent eNB or HeNB.

  The control unit 321 manages each of these functional blocks.

  FIG. 5 is a diagram schematically illustrating radio bands used by the eNB 200 and the HeNB 300. Since the radio bands used by the eNB 200 and the HeNB 300 overlap on the frequency axis, the radio waves interfere with each other in the overlapping portion.

  FIG. 6 is a diagram illustrating units of radio resources managed by the eNB 200 and the HeNB 300. Radio resources can be represented by a time axis 500 and a frequency axis 510. The time axis 500 is divided in units of subframes 501. On the other hand, the frequency axis 510 is divided in units of subcarriers 511.

  One block divided by the subframe 501 and the plurality of subcarriers 511 is referred to as a resource block 521.

  FIG. 7 is a diagram showing radio channels used in the present embodiment. A downlink reference channel (Downlink Reference Channel) 1001 is a radio channel for monitoring an interference state with the eNB 200 by the HeNB 300. The uplink shared channel (Uplink Shared Channel) 1002 and the downlink shared channel (Downlink Shared Channel) 1003 are radio channels for performing communication between the HeNB 300 and the eNB 200.

(Operation)
With reference to the drawings, operations of the eNB 200 and the HeNB 300 will be described. In the present embodiment, the HeNB 300 has the configuration of FIG. 4, and exchanges messages wirelessly with the eNB 200 via the eNB communication unit 323. Note that the case of exchanging messages using a wire will be described in the third embodiment.

  FIG. 8 is a flowchart showing the operation of the HeNB 300 according to the present embodiment. The HeNB 300 determines whether to make a radio resource reservation for the eNB 200 according to the flowchart of FIG.

  The HeNB 300 receives and analyzes the downlink reference channel 1001 that is a reference channel in the downlink direction transmitted by the adjacent eNB 200 at the time of activation or at regular intervals by the downlink channel reception analysis unit 324. The HeNB 300 measures the radio field intensity of the downlink reference channel 1001, and calculates a propagation loss (Path Loss, path loss) between the neighboring macro base station device eNB200 and the HeNB 300 (step S600).

  The HeNB 300 determines whether or not the radio field intensity of the downlink reference channel 1001 received from the neighboring eNB 200 is equal to or higher than the threshold (step S610). If the threshold is equal to or greater than the threshold (Yes in step S610), the HeNB 300 determines that the downlink radio wave of the neighboring eNB 200 is an interference source for the radio wave received by the mobile station terminal 403 connected to the HeNB 300. .

  The HeNB 300 determines whether or not the propagation loss of the downlink reference channel 1001 received from the neighboring eNB 200 is greater than or equal to the threshold (steps S620 and S621). When the threshold is equal to or greater than the threshold (Yes in step S620, Yes in step S621), the HeNB 300 transmits the uplink radio wave transmitted by the mobile station terminal 403 connected to the HeNB 300 to the radio wave received by the neighboring eNB 200. Judged to be an interference source.

  When both the radio field intensity and the propagation loss are less than the threshold (No in Step S610, No in Step S620), the HeNB 300 determines that no interference occurs between the HeNB 300 and the eNB 200, and reserves resources. Not performed (step S630).

  When only the propagation loss is equal to or greater than the threshold (No in step S610, Yes in step S620), the HeNB 300 transmits the uplink radio wave transmitted from the mobile station terminal 403 connected to the HeNB 300 to the neighboring macro radio base station apparatus eNB200. Is determined to be a source of interference with the radio wave received by. At this time, the HeNB 300 reserves in advance uplink radio resources used by the eNB 200 for the HeNB 300 (step S631).

  When only the radio wave intensity is equal to or greater than the threshold (Yes in step S610, No in step S621), the HeNB 300 transmits the radio wave in the downlink direction of the neighboring eNB 200 to the radio wave received by the mobile station terminal 403 connected to the HeNB 300. Is determined to be an interference source. At this time, the HeNB 300 reserves downlink radio resources used by the eNB 200 for the HeNB 300 in advance (step S632).

  When both the radio field intensity and the propagation loss are equal to or greater than the threshold (Yes in step S610, Yes in step S621), the HeNB 300 reserves in advance uplink and downlink radio resources used by the eNB 200 for the HeNB 300. (Step S633).

  In addition, when the cover area of HeNB300 overlaps with the cover area of several eNB, HeNB300 performs the process similar to the process shown to the flowchart of FIG. 8 with respect to each eNB.

  FIG. 9 is a sequence chart showing operations of resource allocation and resource release between the HeNB 300 and the eNB 200. FIG. 10 shows the contents of the resource allocation request 700. With reference to FIG.9 and FIG.10, operation | movement which HeNB300 reserves the radio | wireless resource of eNB200 is demonstrated.

  The HeNB 300 transmits a resource allocation request 700 on the uplink shared channel 1002 via the eNB communication unit 323 to reserve the radio resource of the eNB 200.

  This resource allocation request 700 is transmitted immediately after the completion of the processing shown in the flowchart of FIG. 8, is transmitted when the HeNB 300 receives a connection request from the mobile station terminal 403, or the HeNB 300 is the upper device SGW / MME 100. Is transmitted when an incoming call notification is received from the mobile station terminal 403.

  FIG. 10 is a diagram showing the configuration of the resource allocation request in this embodiment. Referring to FIG. 10, the resource allocation request 700 message includes a destination eNB identification ID 2001, a transmission source HeNB identification ID 2002, a necessary resource amount 2003, and a neighboring HeNB cell identification ID list 2004.

  The HeNB 300 monitors the downlink channel of the neighboring cell at startup or periodically, and acquires the cell ID of the neighboring cell. The HeNB 300 generates a destination eNB identification ID 2001 and an adjacent HeNB cell identification ID list 2004 based on the acquired ID.

  When the resource allocation request 700 is transmitted immediately after the completion of the processing shown in the flowchart of FIG. 8, the HeNB 300 satisfies the maximum data rate in the uplink and downlink directions supported by the HeNB 300 as the required resource amount 2003. To be notified.

  On the other hand, when a resource allocation request 700 is transmitted when a connection request is received from the mobile station terminal 403 or an incoming notification is received from the SGW / MME 100, the HeNB 300 is requested from the mobile station terminal 403 or the SGW / MME 100. The resource amount is determined according to the service type.

  As an example, the service type can be distinguished by using QCI (QoS Class Identify) of TS23.203. For example, a resource amount satisfying several tens of kbps is required for audio, a resource amount satisfying about several hundred kbps to several Mbps is required for video, and from several hundred kbps for web browsing. It is preferable to request a resource amount of about several Mbps, and to request the maximum data rate in the uplink or downlink direction supported by the HeNB 300 for upload or download.

  The amount of resource requested in each QCI is preferably held as a parameter whose setting can be changed.

  Note that, as a result of the processing shown in the flowchart of FIG. 8, if the HeNB 300 determines that it is necessary to reserve radio resources for a plurality of eNBs, the HeNB 300 sends a resource allocation request 700 to each eNB. Send.

  FIG. 11 is a flowchart showing the operation of the eNB 200 according to the present embodiment. When receiving the resource allocation request 700, the eNB 200 allocates resources according to the flowchart shown in FIG. 11 (step S750 in FIG. 9).

  The eNB 200 receives the resource allocation request 700 from the HeNB 300 (step S800).

  The eNB 200 determines whether or not radio resources have already been assigned to other HeNBs (step S801).

  When the eNB 200 has not assigned radio resources to other HeNBs (No in step S801), as shown in FIG. Allocates the maximum radio resource amount that can be allocated to the HeNB 300 to the HeNB 300 (step S805). As an example, the eNB 200 may allocate radio resources at a time as illustrated in FIG.

  When radio resources have already been allocated to other HeNBs (Yes in step S801), the eNB 200 has already allocated resources in the neighboring HeNB cell identification ID list 2004 notified by the HeNB 300 in the resource allocation request 700. It is determined whether or not there is a HeNB identification ID (step S802).

  When the corresponding ID does not exist in the adjacent HeNB cell identification ID list 2004 (No in Step 802), the eNB 200 allocates the maximum re-radio source that can be allocated with the required resource amount 2003 or less with respect to the HeNB ID # 1. An amount is assigned (step S804). At this time, as shown in FIG. 13, since the adjacent HeNB has not reserved radio resources, resources that have already been allocated to other HeNBs can be allocated to HeNB ID # 1.

  When there is an already allocated HeNB identification ID in the adjacent HeNB cell identification ID list 2004 notified by the HeNB 300 in the resource allocation request 700 (Yes in step S802), the eNB 200 has already completed as shown in FIG. Among radio resources that do not overlap with radio resources that have already been allocated to other HeNBs, a maximum radio resource amount that can be allocated that is less than or equal to the required resource amount 2003 is allocated (step S803).

  After determining the radio resource to be allocated according to the flowchart illustrated in FIG. 11, the eNB 200 transmits a resource allocation response 701 to the HeNB 300. FIG. 14 is a diagram illustrating a configuration of a resource allocation response in the present embodiment. Referring to FIG. 14, the resource allocation response 701 includes a destination HeNB identification ID 3001, a transmission source eNB identification ID 3002, and an assigned resource amount 3003.

  When the use of the radio resource is terminated, the HeNB 300 transmits a resource release request 702 to the eNB 200 via the uplink shared channel 1002 to notify that the use of the radio resource is terminated.

  After receiving the resource release request 702, the eNB 200 releases the resource allocated in the resource allocation (step S750 in FIG. 9) to the HeNB ID, and sends a resource release response 703 to the HeNB 300 via the downlink shared channel 1003. Send back.

  When interference with the adjacent eNB 200 is expected, the HeNB 300 requests the eNB 200 to allocate radio resources in the above flow, and uses only the allocated radio resources to move under the HeNB 300. Data communication with the station terminal 403 is performed. At this time, the data rate between HeNB300 and the mobile station terminal 403 is restrict | limited by the allocated radio | wireless resource.

(effect)
In the present embodiment, the home radio base station apparatus reserves frequency carriers (radio resources) to the macro radio base station apparatus in order to avoid interference with the macro radio base station apparatus.

  By reserving the frequency carrier (radio resource) only when necessary, the period for allocating the frequency carrier (radio resource) to the home radio base station apparatus is limited. Therefore, even if installation of a home wireless base station apparatus is installed, the data rate that can be provided by the macro wireless base station apparatus is not significantly reduced.

  Further, in this embodiment, when the home radio base station apparatus is not adjacent, the macro radio base station apparatus performs resource scheduling such that the same frequency carrier (radio resource) is allocated redundantly. This can be realized, for example, by the home wireless base station device notifying the macro wireless base station device of the adjacent home wireless base station device ID. At this time, even if a plurality of home radio base station apparatuses are installed under the macro radio base station apparatus, the data rate that can be provided by the macro radio base station apparatus does not decrease in proportion to the number of HeNBs. .

  Furthermore, in this embodiment, the home radio base station apparatus changes the amount of frequency carriers (radio resources) to be reserved according to the service requested by the mobile station terminal. That is, the home radio base station apparatus notifies the macro radio base station apparatus of the necessary resource amount. This can be realized, for example, by defining a required resource amount according to QCI (QoS Class Indentity) and notifying the macro radio base station apparatus of the required resource amount. In this case, it is possible to avoid unnecessary resource reservations such as reservation of tens of Mbps for voice data communication.

  From the above, according to the radio communication system according to the present embodiment, not only can the interference problem between the macro radio base station apparatus and the home radio base station apparatus be avoided, but the macro radio base station apparatus can be used. The amount of decrease in frequency carrier can be suppressed. The home radio base station apparatus requests a required resource amount for each service, and the macro radio base station apparatus allocates the same radio carrier to a plurality of non-adjacent home radio base station apparatuses. is there. Further, by requesting resource allocation whenever the home radio base station apparatus needs, it is also possible to shorten the period during which the frequency carriers available in the macro radio base station apparatus decrease.

(Embodiment 3)
A radio base station apparatus according to the third embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the message resource allocation request 700, the resource allocation response 701, the resource release request 702, and the resource release response 703 shown in FIG. 9 are the uplink shared channels of the radio channels shown in FIG. 1002 and the downlink shared channel 1003. On the other hand, transmission / reception can also be performed via a wired line (S1 interface) that connects between the HeNB 300 and the SGW / MME 100 and between the eNB 200 and the SGW / MME 100.

  FIG. 17 is a block diagram showing the configuration of the home radio base station apparatus according to this embodiment. FIG. 17 is a block diagram illustrating a configuration of a home radio base station apparatus when exchanging messages with the eNB 200 via a wired line. In this case, unlike the configuration illustrated in FIG. 4, the HeNB 300 does not include the eNB communication unit 323 that performs radio signal transmission / reception with the eNB 200.

  In the present embodiment, a resource allocation request, a resource reservation response, a resource release request, and a resource release response are added as new messages to the application protocol (Application Protocol) on the S1 interface.

(Embodiment 4)
A radio base station apparatus according to the fourth embodiment of the present invention will be described with reference to the drawings. With respect to the processing 803, processing 804, and processing 805 in the flow of FIG. 11, in the previous embodiment, as shown in FIG. 15, the maximum assignable radio resource amount below the required resource amount 2003 is assigned at a time. . FIG. 18 is a diagram for explaining a resource allocation method according to this embodiment. As shown in FIG. 18, it is also possible to define radio resource allocation units in advance and allocate radio resources in stages in units defined in advance each time a resource allocation request 700 is received.

  When a maximum resource that can be allocated is allocated when a resource allocation request is received, the higher the order in which the resource allocation request 700 is received, the higher the possibility that more radio resources can be allocated. On the other hand, by allocating radio resources in stages, the radio resource allocation amount between HeNBs can be equalized.

(Embodiment 5)
A radio base station apparatus according to a fifth embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the minimum unit of radio resources that the macro radio base station apparatus allocates to the home radio base station apparatus is based on the resource block 521 as shown in FIG. FIG. 19 is a diagram for explaining a resource allocation unit in the present embodiment. As shown in FIG. 19, the subframe 501 may be the minimum unit.

  Here, the resource block 521 refers to a block divided by a subframe 501 and 12 subcarriers 511. To use one resource block means to use 12 subcarriers 511 in one subframe (1 ms) section.

  The use of one subframe means that all subcarriers 511 are used over one subframe (1 ms) section regardless of the number of subcarriers 511.

  Although the above description has been made based on the embodiment, the present invention is not limited to the above embodiment.

  It should be noted that the disclosures of the above patent documents are incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. Various combinations and selections of various disclosed elements are possible within the scope of the claims of the present invention. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea.

  In addition, although a part or all of the said embodiment can be described as the following additional remarks, it is not limited to these.

(Supplementary note 1) a first radio base station apparatus that covers the first cell;
A second radio base station apparatus that covers a second cell that is wider than the first cell and at least partially overlaps the first cell;
When the first radio base station apparatus communicates with a mobile station terminal included in the first cell, the first radio base station apparatus refers to the communication quality of the second cell and When determining whether or not to reserve a radio resource and determining that the reservation of the radio resource is necessary, a radio resource allocation request including a necessary resource amount is transmitted to the second radio base station device,
When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus sends radio resources corresponding to the necessary resource amount to the first radio base station apparatus. A wireless communication system characterized by allocating.

  (Supplementary note 2) The wireless communication system according to supplementary note 1, wherein the communication quality is radio field intensity and propagation loss in a downlink reference channel of the second cell.

  (Appendix 3) The first radio base station apparatus reserves downlink radio resources of the second radio base station apparatus when the radio field intensity is a predetermined threshold value or more. The radio communication system according to appendix 1 or 2.

  (Appendix 4) The first radio base station apparatus reserves uplink radio resources of the second radio base station apparatus when the propagation loss is equal to or greater than a predetermined threshold. The wireless communication system according to any one of appendices 1 to 3.

  (Supplementary note 5) Any one of Supplementary notes 1 to 4, wherein the necessary resource amount is a resource amount that satisfies a maximum data rate in uplink and downlink directions supported by the first radio base station apparatus. A wireless communication system according to claim 1.

  (Supplementary note 6) The wireless communication system according to any one of Supplementary notes 1 to 4, wherein the necessary resource amount is a resource amount corresponding to a service type requested from the mobile station terminal.

  (Supplementary note 7) The required resource amount is a resource amount according to a service type requested from a higher-order control device of the first radio mobile station device and the second radio mobile station device. The wireless communication system according to any one of appendices 1 to 4.

  (Supplementary note 8) When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus sends the first radio base station apparatus with the necessary resource amount or less. The wireless communication system according to any one of appendices 1 to 7, wherein a maximum assignable wireless resource is assigned.

  (Supplementary Note 9) When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus covers the third radio base station that has already allocated radio resources. When the third cell to be executed and the first cell do not overlap, the first radio base station transmits a radio resource that overlaps at least partly with the radio resource allocated to the third radio base station. The wireless communication system according to any one of appendices 1 to 8, wherein the wireless communication system is assigned to a station.

  (Supplementary Note 10) The second radio base station apparatus sequentially assigns radio resources of a predetermined resource amount each time the radio resource allocation request is received from the first radio base station apparatus. The wireless communication system according to any one of appendices 1 to 9.

  (Supplementary note 11) The radio communication system according to any one of Supplementary notes 1 to 10, wherein the second radio base station apparatus allocates radio resources in units of resource blocks.

  (Supplementary note 12) The radio communication system according to any one of Supplementary notes 1 to 10, wherein the second radio base station apparatus allocates radio resources in units of subframes.

  (Supplementary note 13) The wireless communication according to any one of Supplementary notes 1 to 12, wherein the first radio base station device and the third radio base station device are home radio base station devices. system.

  (Supplementary note 14) The radio communication system according to any one of supplementary notes 1 to 13, wherein the second radio base station apparatus is a macro radio base station apparatus.

(Supplementary note 15) A radio base station apparatus covering a first cell,
When communicating with a mobile station terminal included in the first cell, the communication quality of a second cell that is wider than the first cell and overlaps the first cell at least in part , It is determined whether or not the radio resource of the second radio base station apparatus covering the second cell should be reserved, and when it is determined that the radio resource needs to be reserved, the second radio A radio base station apparatus that transmits a radio resource allocation request including a necessary resource amount to the base station apparatus.

(Additional remark 16) The 2nd radio base which covers the 2nd cell which is a cell wider than the 1st cell covered by the 1st radio base station apparatus, and at least partially overlapped with the 1st cell A station device,
When a radio resource allocation request including a resource amount necessary for the first radio base station device is received from the first radio base station device, the first radio base station device is provided with the necessary resource amount. A radio base station apparatus characterized by allocating radio resources according to the above.

(Supplementary Note 17) When the first radio base station apparatus covering the first cell communicates with the mobile station terminal included in the first cell, the cell is wider than the first cell. Determining whether to reserve radio resources of the second radio base station apparatus covering the second cell with reference to the communication quality of the second cell that overlaps the first cell at least in part And a process of
A step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus when the first radio base station apparatus determines that the radio resource reservation is necessary; ,
When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the radio resource corresponding to the necessary resource amount is sent to the first radio base station apparatus. And a step of assigning a wireless communication method.

(Supplementary Note 18) When the first radio base station apparatus covering the first cell communicates with the mobile station terminal included in the first cell, the cell is wider than the first cell. Determining whether to reserve radio resources of the second radio base station apparatus covering the second cell with reference to the communication quality of the second cell that overlaps the first cell at least in part And a process of
A step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus when the first radio base station apparatus determines that the radio resource reservation is necessary; And a wireless communication method.

(Additional remark 19) The 2nd radio base which covers the 2nd cell which is a cell wider than the 1st cell covered by the 1st radio base station apparatus, and overlapped with the 1st cell in at least one part A station apparatus receiving a radio resource allocation request including a resource amount required in the first radio base station apparatus from the first radio base station apparatus;
The second radio base station apparatus includes a step of allocating radio resources according to the required resource amount to the first radio base station apparatus.

(Supplementary note 20) When communicating with a mobile station terminal included in the first cell covered by the first radio base station apparatus, the cell is wider than the first cell, and at least in part A process of determining whether or not to reserve radio resources of a second radio base station apparatus that covers the second cell with reference to the communication quality of the second cell that overlaps the first cell;
When it is determined that the reservation of the radio resource is necessary, a process of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus, the first radio base station apparatus A program that is executed by a CPU.

(Supplementary Note 21) Processing for receiving from the first radio base station apparatus a radio resource allocation request including a resource amount required in the first radio base station apparatus covering the first cell;
A process of allocating radio resources according to the required resource amount to the first radio base station apparatus, the cell being wider than the first cell and at least partially overlapping the first cell A program that is executed by a CPU of a second radio base station apparatus that covers two cells.

DESCRIPTION OF SYMBOLS 10 Radio | wireless communications system 11 1st radio base station apparatus 12 2nd radio base station apparatus 21 1st cell 22 2nd cell 100 Gateway / handover control apparatus (SGW / MME)
200 Macro radio base station apparatus (eNB)
220, 320 Transport transmission / reception units 221, 321 Control unit 222 Resource scheduling unit 223 Radio signal transmission / reception unit 210 eNB cover area 300-302 Domestic radio base station apparatus (HeNB)
322 mobile station terminal communication unit 323 eNB communication unit 324 downlink channel reception analysis units 310 to 312 HeNB cover areas 400 to 405 mobile station terminal 500 time 501 subframe 510 frequency 511 subcarrier 521 resource block 700 resource allocation request 701 resource allocation response 702 Resource release request 703 Resource release response 1001 Downlink reference channel (Downlink Reference Channel)
1002 Uplink Shared Channel (Uplink Shared Channel)
1003 Downlink Shared Channel (Downlink Shared Channel)
2001 Destination eNB identification ID
2002 Transmission source HeNB identification ID
2003 Required resource amount 2004 Neighboring HeNB cell identification ID list 3001 Destination HeNB identification ID
3002 Source eNB identification ID
3003 Amount of resources granted

Claims (21)

A first radio base station apparatus covering a first cell;
A second radio base station apparatus that covers a second cell that is wider than the first cell and at least partially overlaps the first cell;
When the first radio base station apparatus communicates with a mobile station terminal included in the first cell, the first radio base station apparatus refers to the communication quality of the second cell and When determining whether or not to reserve a radio resource and determining that the reservation of the radio resource is necessary, a radio resource allocation request including a necessary resource amount is transmitted to the second radio base station device,
When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus sends radio resources corresponding to the necessary resource amount to the first radio base station apparatus. A wireless communication system characterized by allocating.   The wireless communication system according to claim 1, wherein the communication quality is a radio wave intensity and a propagation loss in a downlink reference channel of the second cell.   The first radio base station apparatus reserves downlink radio resources of the second radio base station apparatus when the radio field intensity is a predetermined threshold value or more. The wireless communication system according to 2.   The first radio base station apparatus reserves uplink radio resources of the second radio base station apparatus when a propagation loss is equal to or greater than a predetermined threshold. 4. The wireless communication system according to claim 1.   5. The resource amount according to claim 1, wherein the necessary resource amount is a resource amount that satisfies a maximum data rate in the uplink and downlink directions supported by the first radio base station apparatus. The wireless communication system according to 1.   The wireless communication system according to any one of claims 1 to 4, wherein the required resource amount is a resource amount corresponding to a service type requested from the mobile station terminal.   The required resource amount is a resource amount corresponding to a service type requested from a higher-level control device of the first radio mobile station device and the second radio mobile station device. The wireless communication system according to any one of 1 to 4.   When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus allocates to the first radio base station apparatus less than the necessary resource amount. The radio communication system according to any one of claims 1 to 7, wherein the maximum possible radio resource is allocated.   When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the second radio base station apparatus is covered by a third radio base station that has already allocated radio resources. When the first cell and the first cell do not overlap, a radio resource that at least partially overlaps the radio resource allocated to the third radio base station is allocated to the first radio base station The wireless communication system according to claim 1, wherein:   The second radio base station apparatus sequentially allocates radio resources of a predetermined resource amount each time the radio resource allocation request is received from the first radio base station apparatus. The wireless communication system according to any one of 9.   The radio communication system according to claim 1, wherein the second radio base station apparatus allocates radio resources in units of resource blocks.   The radio communication system according to any one of claims 1 to 10, wherein the second radio base station apparatus allocates radio resources in units of subframes.   The wireless communication system according to any one of claims 1 to 12, wherein the first wireless base station device and the third wireless base station device are home wireless base station devices.   The radio communication system according to claim 1, wherein the second radio base station apparatus is a macro radio base station apparatus. A radio base station apparatus covering a first cell,
When communicating with a mobile station terminal included in the first cell, the communication quality of a second cell that is wider than the first cell and overlaps the first cell at least in part , It is determined whether or not the radio resource of the second radio base station apparatus covering the second cell should be reserved, and when it is determined that the radio resource needs to be reserved, the second radio A radio base station apparatus that transmits a radio resource allocation request including a necessary resource amount to the base station apparatus. A second radio base station apparatus that covers a second cell that is wider than the first cell covered by the first radio base station apparatus and at least partially overlaps the first cell. And
When a radio resource allocation request including a resource amount necessary for the first radio base station device is received from the first radio base station device, the first radio base station device is provided with the necessary resource amount. A radio base station apparatus characterized by allocating radio resources according to the above. When the first radio base station apparatus covering the first cell communicates with the mobile station terminal included in the first cell, the cell is a cell wider than the first cell and at least a part Determining whether or not to reserve radio resources of the second radio base station apparatus that covers the second cell with reference to the communication quality of the second cell that overlaps the first cell at
A step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus when the first radio base station apparatus determines that the radio resource reservation is necessary; ,
When the second radio base station apparatus receives the radio resource allocation request from the first radio base station apparatus, the radio resource corresponding to the necessary resource amount is sent to the first radio base station apparatus. And a step of assigning a wireless communication method. When the first radio base station apparatus covering the first cell communicates with the mobile station terminal included in the first cell, the cell is a cell wider than the first cell and at least a part Determining whether or not to reserve radio resources of the second radio base station apparatus that covers the second cell with reference to the communication quality of the second cell that overlaps the first cell at
A step of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus when the first radio base station apparatus determines that the radio resource reservation is necessary; And a wireless communication method. A second radio base station apparatus that covers a second cell that is wider than the first cell covered by the first radio base station apparatus and overlaps with the first cell at least in part, Receiving from the first radio base station apparatus a radio resource allocation request including a resource amount required in the first radio base station apparatus;
The second radio base station apparatus includes a step of allocating radio resources according to the required resource amount to the first radio base station apparatus. When communicating with a mobile station terminal included in the first cell covered by the first radio base station apparatus, the first cell is at least partially wider than the first cell. A process of determining whether or not to reserve radio resources of the second radio base station apparatus that covers the second cell with reference to the communication quality of the second cell that overlaps with the second cell;
When it is determined that the reservation of the radio resource is necessary, a process of transmitting a radio resource allocation request including a necessary resource amount to the second radio base station apparatus, the first radio base station apparatus A program that is executed by a CPU. A process of receiving a radio resource allocation request including a resource amount required by the first radio base station apparatus covering the first cell from the first radio base station apparatus;
A process of allocating radio resources according to the required resource amount to the first radio base station apparatus, the cell being wider than the first cell and at least partially overlapping the first cell A program that is executed by a CPU of a second radio base station apparatus that covers two cells.

Images